The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference.
Bioactive glasses have been tested as substitutes for reconstruction of defects of the facial bones (1), rehabilitation of the dentoalveolar complex (2), regeneration of periodontal pockets (3), and recently also for treatment of hypersensitive teeth (4). The surface reactive bioactive glass contains SiO.sub.2, Na.sub.2 O, CaO and P.sub.2 O.sub.5. The chemical bond with bone in vivo is reported to result from the leaching of Na.sup.+ -ions and the congruent dissolution of calcium, phosphate and silica from the glass in an aqueous environment, giving rise to an Si-rich layer on the material. The Si-rich layer acts as a templet for a calcium phosphate precipitation, which then binds to the bone (5). Bioactive glass has been successfully used for reconstructions of closed bone defects, which are not exposed to the external environment after the clinical procedure (1). However, there are a number of conditions for which bioactive glasses are used as therapeutic materials but that, at the same time, are imminently prone to microbial infections. These include clinical conditions such as infected frontal minuses (6), periodontal pockets (3) and hypersensitive teeth as a complication of periodontal treatment or tooth wear that has resulted in the exposure of dentin and dentinal tubules (4). Obviously, the demonstration of any antibacterial activity of the bioactive glass would add to the therapeutic vale of the material in the clinical conditions described. Earlier studies have shown that P. gingivalis is agglutinated in the presence of granules (315-500 .mu.m) of the bioactive glass S53P4 in an aqueous environment due to Ca.sup.+ -ions released from the granules (19,7). The minimum Ca.sup.+ -concentration needed to induce agglutination of P. gingivalis was found to be 0.04 g/l (7). In these studies, however, no reduction of the viability of the bacteria was noticed.
Earlier studies have shown that the bioactive glass can act as a vehicle for Ca.sup.2+, PO.sub.4.sup.3-, Na.sup.+ and Si.sup.4+, which then mineralise type I collagen and enhance mineral formation in the dentinal tubules. Therefore, an aqueous preparation comprising bioactive glass may have potential to be used as a paste for the treatment of hypersensitive teeth with recessed gingival margins and exposed dentins. Positive affects of such a treatment have been obtained already after 10 to 60 min, which makes this particular material interesting even from a clinical point of view (4).